Neutral Components Research Articles

A high-resolution spectroscopic system for remote measurement of plasma parameters.

Plasma diagnostics are usually performed with immersive probes that collect the cumulative electric currents created by charged particles. Idealized models are applied to the resulting I-V curves to extract plasma flow parameters. Our non-invasive technique, based on passive emission spectroscopy (PES), allows for the remote measurement of undisturbed plasma parameters via fine spectral effects. Importantly, it can be applied to each plasma species separately, including neutral components. However, extremely high spectral resolution is required to resolve shapes of the spectral lines. We describe a portable instrumentation system that delivers sub-pm resolution in visible and near-infrared regions of the spectrum. It can be used to measure various plasma parameters but most notably allows the drift velocities of ions and neutrals to be resolved with ∼100 m/s precision. We discuss details of our experimental apparatus, along with capabilities and limitations of the PES implementation.

Using small samples to estimate neutral component size and robustness in the genotype-phenotype map of RNA secondary structure.

In genotype-phenotype (GP) maps, the genotypes that map to the same phenotype are usually not randomly distributed across the space of genotypes, but instead are predominantly connected through one-point mutations, forming network components that are commonly referred to as neutral components (NCs). Because of their impact on evolutionary processes, the characteristics of these NCs, like their size or robustness, have been studied extensively. Here, we introduce a framework that allows the estimation of NC size and robustness in the GP map of RNA secondary structure. The advantage of this framework is that it only requires small samples of genotypes and their local environment, which also allows experimental realizations. We verify our framework by applying it to the exhaustively analysable GP map of RNA sequence length L = 15, and benchmark it against an existing method by applying it to longer, naturally occurring functional non-coding RNA sequences. Although it is specific to the RNA secondary structure GP map in the first place, our framework can probably be transferred and adapted to other sequence-to-structure GP maps.

Salinity Improves Zinc Resistance in Kosteletzkya pentacarpos in Relation to a Modification in Mucilage and Polysaccharides Composition

The halophyte plant species Kosteletzkya pentacarpos produces high amounts of mucilage which may play a role in heavy metal tolerance. The amount and composition of mucilage in K. pentacarpos exposed to zinc toxicity in the presence or in the absence of 50 mM NaCl was investigated. Exposure to 0.1 mM Zn had a detrimental impact on plants growth and water content. Most of Zn was accumulated in the roots of plants exposed to Zn toxicity both in the absence and in the presence of NaCl. Salinity, however, partially alleviated the toxicity of zinc, increasing the plant biomass and decreasing zinc absorption by the root. Crude mucilage content increased in all plant organs in response to Zn stress. Acid hydrolysis of crude mucilage extract revealed that the main neutral monosaccharide constituents were rhamnose, arabinose, galactose, and glucose. Zinc induced a rise in uronic acids in roots and stems but not in the leaves where a high constitutive proportion of uronic acids was observed. Meanwhile, changes were also observed in neutral monosaccharides component in different plant organs. Zinc stress increased the hemicellulose content, but decreased the lignin and cellulose content in the stem. Salinity slightly increased the cellulose content. We suggest that excessive zinc induces a modification in the composition and structure of polysaccharides and that mucilage may contribute to Zn tolerance through toxic ion sequestration.

Constraints on long-lived light scalars with flavor-changing couplings and the KOTO anomaly

Recently, the KOTO experiment at J-PARC has observed three anomalous events in the flavor-changing rare decay $K_L \to \pi^0 \nu \bar\nu$, which indicates that the corresponding branching ratio is almost two orders of magnitude larger than the Standard Model (SM) prediction. Taking this intriguing result at face value, we explore model implications of its viable explanation by a long-lived light SM-singlet scalar ($S$) emission, i.e. $K_L \to \pi^0 S$, with $S$ decaying outside the KOTO detector. We derive constraints on the parameter space of such a light scalar in the context of three simple models: (i) a real singlet scalar extension of the SM; (ii) a $B-L$ extension where neutrino masses arise via type-I seesaw mechanism from $B-L$ breaking; and (iii) a TeV-scale left-right symmetric model. The flavor-changing couplings needed to explain the KOTO excess in models (i) and (ii) originate from tree-level mixing of the scalar with SM Higgs field ($h$), and in model (iii), from the mixing of $S$ and $h$ with the neutral component of the heavy bidoublet Higgs field. After taking into account the stringent constraints from high-precision searches for flavor-changing charged and neutral kaon decays at NA62, E949, KOTO and CHARM experiments, as well as the astrophysical and cosmological constraints on a light scalar, such as those from supernova energy loss, big bang nucleosynthesis and relativistic degrees of freedom, we find that the light scalar interpretation of the KOTO excess is allowed in all these models. Parts of the parameter range can be tested in future NA62 and DUNE experiments.

Bases, solvates and salts: new benzimidazole- and pyridine-scaffolded ligands.

The intermolecular interactions in the structures of a series of Schiff base ligands have been thoroughly studied. These ligands can be obtained in different forms, namely, as the free base 2-[(2E)-2-(1H-imidazol-4-ylmethylidene)-1-methylhydrazinyl]pyridine, C10H11N5, 1, the hydrates 2-[(2E)-2-(1H-imidazol-2-ylmethylidene)-1-methylhydrazinyl]-1H-benzimidazole monohydrate, C12H12N6·H2O, 2, and 2-{(2E)-1-methyl-2-[(1-methyl-1H-imidazol-2-yl)methylidene]hydrazinyl}-1H-benzimidazole 1.25-hydrate, C13H14N6·1.25H2O, 3, the monocationic hydrate 5-{(1E)-[2-(1H-1,3-benzodiazol-2-yl)-2-methylhydrazinylidene]methyl}-1H-imidazol-3-ium trifluoromethanesulfonate monohydrate, C12H13N6+·CF3O3S-·H2O, 5, and the dicationic 2-{(2E)-1-methyl-2-[(1H-imidazol-3-ium-2-yl)methylidene]hydrazinyl}pyridinium bis(trifluoromethanesulfonate), C10H13N52+·2CF3O3S-, 6. The connection between the forms and the preferred intermolecular interactions is described and further studied by means of the calculation of the interaction energies between the neutral and charged components of the crystal structures. These studies show that, in general, the most important contribution to the stabilization energy of the crystal is provided by π-π interactions, especially between charged ligands, while the details of the crystal architecture are influenced by directional interactions, especially relatively strong hydrogen bonds. In one of the structures, a very interesting example of the nontypical F...O interaction was found and its length, 2.859 (2) Å, is one of the shortest ever reported.

Singlet-doublet fermionic dark matter and gravitational waves in a two-Higgs-doublet extension of the Standard Model

We present a study of singlet-doublet vector-like leptonic dark matter (DM) in the framework of two Higgs doublet model (2HDM), where the dark sector is comprised of one doublet and one singlet vectorlike fermions (VLFs). The DM, that arises as an admixture of the neutral components of the VLFs, is stabilized by an imposed discrete symmetry $\mathcal{Z}_2^{'}$ . We test the viability of the model in the light of observations from PLANCK and recent limits on spin-independent direct detection experiments, and search for its possible collider signals. In addition, we also look for the stochastic gravitational wave (GW) signatures resulting from strong first order phase transition due to the presence of the second Higgs doublet. The model thus offers a viable parameter space for a stable DM candidate that can be probed from direct search, collider and GW experiments.

‘Bolder’ together — response to human social cues in groups of free-ranging dogs

Abstract In urban environments, humans are a part of an interaction network of several species, impacting them directly or indirectly. The positive, negative and neutral components of such impact can be assessed by studying human-animal interactions in various habitats. While studies have shown animals’ reactions to specific human social cues, information is lacking on how animals respond to such cues in the presence and absence of conspecifics. We investigated the behavioural responses of free-ranging dogs (Canis lupus familiaris) towards various human social cues (neutral, friendly, low- and high-impact threatening) when presented to groups. We used previously published data on dogs’ reactions to identical cues when presented solitarily, and compared them with the group-level responses. Our results strengthen the idea of situation-relevant responsiveness in free-ranging dogs. Dogs in groups exhibited higher approach and less avoidance towards the unfamiliar human experimenter, especially towards the threatening cues, compared to dogs tested alone.

Two component dark matter with inert Higgs doublet: neutrino mass, high scale validity and collider searches

The idea of this work is to investigate the constraints on the dark matter (DM) allowed parameter space from high scale validity (absolute stability of Higgs vacuum and perturbativity) in presence of multi particle dark sector and heavy right handed neutrinos to address correct neutrino mass. We illustrate a simple two component DM model, consisting of one inert SU(2)L scalar doublet and a scalar singlet, both stabilised by additional {mathcal{Z}}_2times {mathcal{Z}}_2^{prime } symmetry, which also aid to vacuum stability. We demonstrate DM-DM interaction helps achieving a large allowed parameter space for both the DM components by evading direct search bound. High scale validity puts further constraints on the model, for example, on the mass splitting between the charged and neutral component of inert doublet, which has important implication to its leptonic signature(s) at the Large Hadron Collider (LHC).

Evaluation on the Quasi‐Realistic Ionospheric Prediction Using an Ensemble Kalman Filter Data Assimilation Algorithm

AbstractIn this work, we evaluated the quasi‐realistic ionosphere forecasting capability by an ensemble Kalman filter (EnKF) ionosphere and thermosphere data assimilation algorithm. The National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model is used as the background model in the system. The slant total electron contents (TECs) from global International Global Navigation Satellite Systems Service ground‐based receivers and from the Constellation Observing System for Meteorology, Ionosphere and Climate are assimilated into the system, and the ionosphere is then predicted in advance during the quiet interval of 23 to 27 March 2010. The predicted ionosphere vertical TEC (VTEC) and the critical frequency foF2 are validated by the Massachusetts Institute of Technology VTEC and global ionosondes network, respectively. We found that the ionosphere forecast quality could be enhanced by optimizing the thermospheric neutral components via the EnKF method. The ionosphere electron density forecast accuracy can be improved by at least 10% for 24 hr. Furthermore, the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Global Ultraviolet Imager (TIMED/GUVI) [O/N2] observations are used to validate the predicted thermosphere [O/N2]. The validation shows that the [O/N2] optimized by EnKF has better agreement with the TIMED/GUVI observation. This study further demonstrates the validity of EnKF in enhancing the ionospheric forecast capability in addition to our previous observing system simulation experiments by He et al. (2019, https://doi.org/10.1029/2019JA026554).

Non-Abelian vector boson as FIMP dark matter

In this analysis we demonstrate the freeze-in realization of a non-abelian vector boson dark matter (DM). We choose to elaborate an existing SU(2)N extension (N stands for neutral) of the Standard Model (SM) with an additional U(1)=S′ global symmetry, which stabilizes the vector boson (X,X̄) as DM through unbroken S=T3N+S′ as the lightest odd S particle. Apart from showing the right order of the SU(2)N coupling (∼ 10−12–10−13) required for the correct relic of DM via freeze in, the analysis reveals that the contribution to the freeze-in production of DM from the decay of a heavier scalar bi-doublet ζ10,± → ζ20,±X is equally important even after the decoupling of ζ10,± from the thermal bath. This treatment of computing the relic abundance in context with freeze-in is practically model-independent and can be applied to all the scenarios where the DM is produced from the decay of a massive particle which was once in equilibrium with the thermal bath. This bi-doublet earlier was in equilibrium with the visible sector due to SM SU(2)L coupling. Moreover, the neutral component of SU(2)N scalar triplet (Δ), responsible for neutrino mass generation in this framework, turns out to serve as additional DMs in the model and offers a multipartite freeze-in DM set up to explore. The allowed parameter space is obtained after estimating constraints from CMB, BBN and AMS-02 bound. This exercise nicely complements the freeze-out realization of (X,X̄) as weakly interacting massive particle (WIMP) and distinguishes it through stable charge track signature at collider compared to leptonic signal excess as in WIMP scenario.

Formation and Corrosion Behavior of Nickel/Alumina Nanocomposites

Ni nanopillars (Ni NPs) composite materials formation technology was presented. The morphological and structural properties of the composite material were investigated using scanning electron microscopy, atomic force microscopy, X-ray diffraction. The corrosion resistance of the nanocomposite materials has been studied by potentiodynamic polarization curves analysis. The composite represents the array of vertically ordered Ni NPs with the identical size in alumina matrix. XRD investigation indicates that Ni NPs are polynanocrystalline material. It has been shown that Ni NPs and the composite material have sufficient corrosion resistance in a 0.9% aqueous NaCl solution. Porous alumina matrix is the neutral and protective component of the composite. These nanocomposite materials can be excellent candidates for practical use in different applications.

Theory of Holographic Formation in Multicomponent Photopolymer-Based Nanocomposites-=SUP=-*-=/SUP=-

The derivation of the three-component (monomer, chemically neutral component, and polymer) photopolymerization model from general thermodynamic considerations is presented. This model, together with another previously published one, are subject to a numerical solution for the case of a two-component one-dimensional diffusion (polymer component being steady). The divergence of results of work for both models was compared based on the average speed of the root-mean-square deviation in the spatial spectrum domain for relative volume fraction functions for all three components. Such a comparison was performed for 81 pairs of initial relative amount of neutral component and effective diffusion coefficient. The results of the work may serve as a good guide for the choice of parameters of experiments, which are aimed to verify the correctness of the modified theory. Keywords: photopolymerization, photoformer, holographic grating, multicomponent diffusion, polymer, holography.

ЧИСЛЕННОЕ МОДЕЛИРОВАНИЕ РАСПРОСТРАНЕНИЯ УДАРНОЙ ВОЛНЫ ИЗ ГАЗА В ЭЛЕКТРИЧЕСКИ ЗАРЯЖЕННУЮ И НЕЙТРАЛЬНУЮ ГАЗОВЗВЕСИ В ПЛОСКОМ КАНАЛЕ

In this paper, we consider the propagation of a shock wave from a pure gas into a heterogeneous mixture consisting of solid particles suspended in a gas and having an electric charge. The applied mathematical model takes into account the speed and thermal interaction of the carrier and dispersed components of the mixture. The force interaction of particles and gas was described by the Stokes force. The carrier medium was described as a viscous compressible heat–conducting gas. The equations of the mathematical model were solved by the explicit finite–difference method of the second order of accuracy, using the non–linear correction of the grid function. The system of equations of the mathematical model was supplemented by boundary and initial conditions for the desired functions. As a result of numerical simulation, it was found that in an electrically charged gas suspension there is a difference in gas pressure and velocity, “average density” and velocity of the dispersed component, compared with similar values in a gas suspension with an electrically neutral dispersed component. The revealed differences in the dynamics of neutral and electrically charged dusty media can be explained by the fact that the dispersed component of an electrically charged gas suspension is affected by both aerodynamic drag forces and Coulomb forces. Due to interfacial interaction, the dynamics of the carrier medium changes.

Boundary conditions for drift-diffusion equations in gas-discharge plasmas

This paper develops a general approach to the derivation of the boundary conditions for hydrodynamic equations for charged and neutral plasma components. It includes both a well-known classical case for pure diffusion and considers the expressions for diffusion and drift together—for an absorbing (neutralizing) wall with partial reflection and the possible emission of plasma components. Some unclear and controversial terms found in the existing literature are clarified. Several examples of applications of the results, which illustrate the properties of boundary conditions for electrons and ions, are calculated and analyzed.

Characteristics of the quasi-16-day wave in the mesosphere and lower thermosphere region as revealed by meteor radar, Aura satellite, and MERRA2 reanalysis data from 2008 to 2017

This study presents an analysis of the quasi-16-day wave (Q16DW) at three stations in the middle latitudes by using a meteor radar chain in conjunction with Aura Microwave Limb Sounder temperature data and MERRA2 (Modern-Era Retrospective Analysis for Research and Applications, Version 2) reanalysis data from 2008 to 2017. The radar chain consists of three meteor radar stations located at Mohe (MH, 53.5°N, 122.3°E), Beijing (BJ, 40.3°N, 116.2°E), and Wuhan (WH, 30.5°N, 114.6°E). The Q16DW wave exhibits similar seasonal variation in the neutral wind and temperature, and the Q16DW amplitude is generally strong during winter and weak around summer. The Q16DW at BJ was found to have secondary enhancement around September in the zonal wind, which is rarely reported at similar latitudes. The latitudinal variations of the Q16DW in the neutral wind and temperature are quite different. The Q16DW at BJ is the most prominent in both neutral wind components among the three stations and the Q16DW amplitudes at MH and WH are comparable, whereas the wave amplitude in temperature decreases with decreasing latitude. The quasi-geostrophic refractive index squared at the three stations in the period from 2008 to 2017 was revealed. The results indicate that the Q16DW in the mesosphere and lower thermosphere (MLT) at MH has a limited contribution from the lower atmosphere. Around March and October, the Q16DW in the troposphere at BJ can propagate upward into the MLT region, whereas at WH, the contribution to the Q16DW in the MLT region is largely from the mesosphere.

Crystallisation of organic salts by sublimation: salt formation from the gas phase

Co-sublimation of two neutral components yields crystals of salts and co-crystals. Experiments show that during sublimation of salts, proton transfer occurs after molecules enter the gas phase.

Dynamics of the Mesosphere and Lower Thermosphere Based on Results of Observations on the SURA Facility

The results of studies of atmospheric dynamics in the altitude range of 60–130 km are presented based on measurements of the velocity of vertical plasma motion, the temperature and density of the neutral component, and the turbopause height. The measurements were carried via resonant scattering of radio waves by artificial periodic inhomogeneities of the ionospheric plasma. The method is based on ionospheric perturbation by powerful high-frequency radio emission, the creation of periodic inhomogeneities in the field of a standing wave, which forms upon reflection from the ionosphere of a powerful radio wave emitted into the zenith, and the location of inhomogeneities by test radio waves. The parameters of the neutral component, the turbulent velocity, and the height of the turbopause are determined from the relaxation time of the signal scattered by the inhomogeneities after the end of the ionospheric impact. The measurement of the phase of the scattered signal makes it possible to determine the rate of vertical plasma motion. The experiments were carried out on a SURA heating facility (56.15° N; 46.11° E). The paper presents and analyzes the time–altitude dependences of the vertical velocity and temperature, which are largely due to the propagation of atmospheric waves during various natural phenomena. The results of determination of the turbopause height and turbulent velocity are presented.

Effect of NaCl, sucrose and pectin addition on the reductive properties of vegetable and fruit puree

Inclusion of minor components in the formulation of homogeneous food systems should inevitably result in some shift of redox equilibrium under conditions of interaction as "all with all." Chemical nature of components combined with properties of elements of medium chemical composition should determine direction and expression of such displacement. But due to the multicomponence of the medium itself and the small initial expression of redox properties for the added components, predicting the resulting properties of the formed food system becomes difficult. The aim of the work was to study the regularities of the influence of neutral minor components on the change of redox properties of homogeneous canned products from vegetable raw materials. Puree-shaped single-component natural canning products (puree) from fruit (apples, plum) and vegetable (pumpkin, carrots) raw materials are taken as research objects. Table salt (NaCl), sucrose and apple pectin were used as minor components. In the obtained canned product, active acidity (pH) and redox potential (Eh) were determined, and the reducing power index (RH) value was calculated. The studies showed that there was no statistically significant effect of NaCl on the redox properties of the food systems studied. There was a statistically significant effect of sucrose on the reducing power index of homogeneous canned puree from plums (in the range up to 18%) and carrots (in the range up to 10%). It has been found that inclusion of pectin in the composition of fruit and vegetable puree does not have a statistically significant effect on the reducing capacity of the product, except for stone fruit puree, for which there was statistically significant single step increase of RH within a weight fraction value of the minor component as 0.61-0.62%. In order to determine the mechanism of such a response, it is necessary to carry out an additional set of targeted studies.

Facial Expression Recognition of Nonlinear Facial Variations Using Deep Locality De-Expression Residue Learning in the Wild

Automatic facial expression recognition is an emerging field. Moreover, the interest has been increased with the transition from laboratory-controlled conditions to in the wild scenarios. Most of the research has been done over nonoccluded faces under the constrained environment, while automatic facial expression is less understood/implemented for partial occlusion in the real world conditions. Apart from that, our research aims to tackle the issues of overfitting (caused by the shortage of adequate training data) and to alleviate the expression-unrelated/intraclass/nonlinear facial variations, such as head pose estimation, eye gaze estimation, intensity and microexpressions. In our research, we control the magnitude of each Action Unit (AU) and combine several of the Action Unit combinations to leverage learning from the generative and discriminative representations for automatic FER. We have also addressed the problem of diversification of expressions from lab controlled to real-world scenarios from our cross-database study and proposed a model for enhancement of the discriminative power of deep features while increasing the interclass scatters, by preserving the locality closeness. Furthermore, facial expression consists of an expressive component as well as neutral component, so we proposed a generative model which is capable of generating neutral expression from an input image using cGAN. The expressive component is filtered and passed to the intermediate layers and the process is called De-expression Residue Learning. The residue in the intermediate/middle layers is very important for learning through expressive components. Finally, we validate the effectiveness of our method (DLP-DeRL) through qualitative and quantitative experimental results using four databases. Our method is more accurate and robust, and outperforms all the existing methods (hand crafted features and deep learning) while dealing the images in the wild.

The Diffuse Ionized Gas Halo of the Small Magellanic Cloud

Abstract Observations with the Wisconsin Mapper reveal a large, diffuse ionized halo that surrounds the Small Magellanic Cloud (SMC). We present the first kinematic survey of an extended region around the galaxy, from to and covering . The ionized gas emission extends far beyond the central stellar component of the galaxy, reaching similar distances to that of the diffuse neutral halo traced by 21 cm observations. emission extends several degrees beyond the sensitivity of current H i surveys toward smaller galactic longitudes and more negative galactic latitudes. The velocity field of the ionized gas near the SMC appears similar to the neutral halo of the galaxy. Using the observed emission measure as a guide, we estimate the mass of this newly revealed ionized component to be roughly , which is comparable to the total neutral mass in the same region of . We find ratios of the total ionized gas mass divided by the total neutral plus ionized gas mass in three distinct subregions to be: (1) 46%–54% throughout the SMC and its extended halo, (2) 12%–32% in the SMC Tail that extends toward the Magellanic Bridge, and (3) 65%–79% in a filament that extends away from the SMC toward the Magellanic Stream. This newly discovered, coherent filament does not appear to have a well-structured neutral component and is also not coincident with two previously identified filaments traced by 21 cm emission within the Stream.